From: Michael Haggerty Date: Wed, 24 Jan 2018 11:14:13 +0000 (+0100) Subject: find_reference_location(): make function safe for empty snapshots X-Git-Tag: v2.17.0-rc0~98^2~3 X-Git-Url: https://git.lorimer.id.au/gitweb.git/diff_plain/4a14f8d093138a313070fd6a50204eda66c1f9eb find_reference_location(): make function safe for empty snapshots This function had two problems if called for an empty snapshot (i.e., `snapshot->start == snapshot->eof == NULL`): * It checked `NULL < NULL`, which is undefined by C (albeit highly unlikely to fail in the real world). * (Assuming the above comparison behaved as expected), it returned NULL when `mustexist` was false, contrary to its docstring. Change the check and fix the docstring. Signed-off-by: Michael Haggerty Signed-off-by: Junio C Hamano --- diff --git a/refs/packed-backend.c b/refs/packed-backend.c index 8beb99652f..fffface428 100644 --- a/refs/packed-backend.c +++ b/refs/packed-backend.c @@ -519,9 +519,11 @@ static int load_contents(struct snapshot *snapshot) * `refname` starts. If `mustexist` is true and the reference doesn't * exist, then return NULL. If `mustexist` is false and the reference * doesn't exist, then return the point where that reference would be - * inserted. In the latter mode, `refname` doesn't have to be a proper - * reference name; for example, one could search for "refs/replace/" - * to find the start of any replace references. + * inserted, or `snapshot->eof` (which might be NULL) if it would be + * inserted at the end of the file. In the latter mode, `refname` + * doesn't have to be a proper reference name; for example, one could + * search for "refs/replace/" to find the start of any replace + * references. * * The record is sought using a binary search, so `snapshot->buf` must * be sorted. @@ -551,7 +553,7 @@ static const char *find_reference_location(struct snapshot *snapshot, */ const char *hi = snapshot->eof; - while (lo < hi) { + while (lo != hi) { const char *mid, *rec; int cmp;